The overall objective of this program is to conduct a "natural" history study to characterize the pulmonary and cardiovascular disorders that occur in association with vertically transmitted (mother to child during gestation or during the perinatal time period) human immunodeficiency virus (HIV) infection in children. The study will be coordinated among six geographically separated centers (Baylor College of Medicine, Houston; Children's Hospital/Harvard Medical School, Boston; Mt. Sinai School of Medicine, New York City; Presbyterian Hospital/Columbia University, New York City; UCLA School of Medicine, Los Angeles; and University of California, San Francisco) and the Clinical Coordinating Center (The Cleveland Clinic Foundation). The Program of the Clinical Coordinating Center will include participation in the development of the study protocol, the detailed manual of operations, appropriate data acquisition via distributed data entry, and establishment of suitable data processing procedures. A major activity of the Clinical Coordinating Center will be the development of procedures for control of the quality of the data. A comprehensive program of data management for the Natural History Study will include data review and editing, reduction, display and analysis, and generation of reports and publications.